#共用的自定义工具类
import functools
from flask import current_app
from flask import g
from flask import session
from info.models import User

def do_index_class(index):
    """返回指定索引对应的类名"""
    if index ==0:
        return "first"
    elif index==1:
        return "second"
    elif index==2:
        return "third"
    return ""
# 定义用户的一个类
def user_login_data(f):
    # 使用functools.wraps去装饰内层函数,可以保持当前装饰器去装饰的函数的__name__的值不变
    @functools.wraps(f)
    def wrapper(*args,**kwargs):
        user_id = session.get("user_id",None)
        user = None
        if user_id:
            # 尝试查询用户的模型
            try:
                user = User.query.get(user_id)
            except Exception as e:
                current_app.logger.error(e)
        g.user = user
        return f(*args,**kwargs)
    return wrapper